Stabilized hydrocarbon oils and waxes



Patented Nov. 25, 1952 ATENT STABILIZED HYDROCARBON OILS AND WAXES ration of Indiana No Drawing. Application April 25, 1951, Serial No. 222,941

The present invention is directed to stabilized hydrocarbon oils and waxes, and more particularly is directed to highly refined hydrocarbon oils and waxes resistant to oxidative deterioration, and to the method of preparing the same.

Highly refined hydrocarbon oils, particularly mineral oils, referred to as White mineral oils, mineral medicinal oils and liquid paraifins are usually prepared by treating petroleum distillates of the desired viscosity with fuming sulfuric acid in amounts ranging from about two pounds to about nine pounds of acid per gallon of oil. White mineral oils or mineral medicinal oils, which will-pass the United States Pharmacopoeia test (referred to as U. S. P. acid test) are usually prepared by treating a distillate stock of from about 100 seconds to about 800 seconds Saybolt Universal viscosity at 100 F., with from about pounds to about 8 pounds of 104 fuming sulfuric acid per gallon of oil. The acid-treated oil, after separation of the acid sludge resulting from the acid treatment, is neutralized with a neutralizing agent, such as caustic soda, washed with alcohol of about 50% to 65% concentration, and then usually treated with an absorbent material, such as clay. Mineral medicinal oils so treated will give a color not greater than 3 NPA by the U. S. P. acid test, which consists of heating 5 cubic centimeters of oil and 5 cubic centimeters of chemically pure sulfuric acid in a glass stopper cylinder for ten minutes in a steam bath maintained at a temperature of 210 F., and shaking at 30 second intervals. At the end of the test period, the oil must remain colorless and the acid must not become darker than pale amber (about 3 NPA). I

In addition to the mineral medicinal oils, other grades of white hydrocarbon oils are made which because of their use, need not pass the U. S. P. acid test. Oils of this type are usually referred to as technical white oils, or commercial white oils, and are usually obtained by treating a hydrocarbon distillate oil, such as petroleum distillate oil of the desired viscosity with from 2 pounds to 5 pounds of turning sulfuric acid per gallon of oil, and neutralizing and washing the neutralized oil with alcohol as above-described in the preparation of medicinal White oils described above.

Due to the drastic refining conditions required in the preparation of white mineral oils, the socalled natural inhibitor-s normally present in mineral oils are removed and as a result these highly refined mineral oils become susceptible to oxidative deterioration. which are used for medicinal purposes in food products, in coatings for paper, and for many White hydrocarbon oils 5 Claims. (Cl;- 252-52) other uses, develop a rancid taste or undesirable odors during storage in the presence of or in the absence of light; this deterioration greatly impairs the utility of such oils. Similarly highly refined paraffin waxes become oxidized and develop rancid odors. It is the purpose of the present invention to treat highly refined hydrocarbon oils and waxes with small amounts of certain inhibitors which inhibit or prevent this oxidative deterioration without affecting the suitability of the oil for its intended use.

It is the primary object of the present invention to provide hydrocarbon oils and waxes which are highly resistant to oxidative deterioration. Another object of the invention is to provide ahighly refined mineral oil which will not become rancid or develop odors upon storage for relatively long periods of time. A further object of the invention is to provide a method of stabilizing mineral white oils and mineral waxes. Other objects and advantages of the present invention will become apparent from the following description thereof.

In accordance with the present invention highly refined hydrocarbon oils and waxes, such as white mineral oils and paraflin waxes and petrolatums are stabilized and made resistant to oxidative deterioration by adding to such oils and waxes a small amount, namely from about 0.000l% to about 0.0025%, by weight, of vitamin K1 hydroquinone. Vitamin K1 hydroquinone is Z-methyl 3 phytyl 1,4 naphthohydroquinone having the probable structure ine effectiveness of the vitamin K1 hydroquinone in inhibiting oxidation of highly refined mineral oils is demonstrated by the data. in the following table:

1 Z-methyl IA-naphthohydroquinone.

The 20 minutes stability test referred to in the above table is a qualitative test to determine the absence or presence of peroxide in the composition being tested. The test is carried out by heating 5 cubic centimeters of the oil in a test tube to a temperature of 300 F. for exactly twenty minutes. The test tube containing the oil sample is then immediately immersed in an ice Water bath for about two minutes to cool the oil to room temperature as rapidly as possible. The air in the test tube is then swept out with a gentle stream of nitrogen, and 5 cubic centimeters of an acetone solution of ferrous sulfate introduced into the test tube and the contents vigorously shaken for about fifteen seconds. The test tube is then set aside to permit Stratification of the liquid in the test tube. If after one minute any pink color shows in the lower layer, the presence of peroxides is indicated and the oil does not pass the test. If the liquid remains colorless, the absence of peroxides is indicated and the oil passes the test.

The 210 stability test indicated in the above table is a test for the quantitative determination of the peroxides formed upon heating the oil at 210 F. for fifty hours. The test is carried out by placing 100 cc. of the oil to .be tested in a clean glass flask which is then placed in a steam bath maintained at a temperature of 210 F. to 212 F. for fifty hours. At the end of the designatedheating period, the flask is removed from the steam bath and the contents allowed to cool to room tem-perature. A cc. portion of the contents is then tested for peroxide oxygen by the following method:

To a clean dry 250 cc. separatory funnel containing 50 cc. of hexane are added 10 grams of the sample to be tested. 5 cc. of an acetone salicylic acid solution are introduced into a funnel and the air displaced with a gentle stream of nitrogen. Ten cubic centimeters of a ferrous chloride reagent are added to the funnel contents and the contents of the funnel vigorously shaken for thirty seconds. Ten cubic centimeters of the clear lower layer from the funnel are then placed in a clean colorimeter tube and read on a Klett photoelectric colorimeter; the galvanometer reading is converted to parts per million peroxide oxygen from a conversion table. The ferrous chloride reagent is prepared by dissolving 4 grams of ferrous chloride in 200 cc. distilled water, adding 50 cc. glacial acetic acid and 500 cc. acetone and adding sufiicient distilled water to make up one liter.

The data in the above table demonstrate the effectiveness of very small amounts of vitamin K1 hydroquinone in inhibiting the oxidation of highly refined mineral oils. For the purpose of comparison, data are included on the oxidation stability of the oil containing vitamin K hydroquinone. It will be noted that whereas vitamin K1 hydroquinone is a very efiective inhibitor, the vitamin K hydroquinone exhibited no oxidation inhibiting properties.

While I have described my invention by reference to a preferred embodiment thereof, the invention is not limited thereby, but includes such variations and modifications as come within the scope of the appended claims.

I claim:

1. A new composition of matter resistant to oxidative deterioration comprising essentially a hydrocarbon material selected from the group consisting of ahydrocarbon oil, a hydrocarbon wax, and mixtures thereof, normally susceptible to oxidative deterioration, and from about 0.0001% to about 0.0025%, by weight, of 2- methyl-3 phytyl, lA-naphthohydroquinone.

2. A hydrocarbon oil composition resistant to oxidative deterioration comprising essentially a hydrocarbon oil normally susceptible to oxidative deterioration, and from about 0.0001% to about 0.0025%, by weight, of 2-methyl-3 phytyl, 1,4-

naphthohydroquinone.

3. A highly refined mineral oil composition resistant to oxidative deterioration comprising essentially a highly refined mineral oil normally susceptible to oxidative deterioration and from about 0.0001% to about 0.0025%, by Weight, of V REFERENCES CITED The following references are of record in the file of this patent:

, UNITED STATES PATENTS Number Name Date 2,363,687 Paul Nov. 28, 1944 2,363,722 Faust Nov. 28, 1944 2,456,686 Doisy Dec. 31, 1948 

1. A NEW COMPOSITION OF MATTER RESISTANT TO OXIDATIVE DETERIORATION COMPRISING ESSENTIALLY A HYDROCARBON MATERIAL SELECTED FROM THE GROUP CONSISTING OF A HYDROCARBON OIL, A HYDROCARBON WAX, AND MIXTURES THEREOF, NORMALLY SUSCEPTIBLE TO OXIDATIVE DETERIORATION, AND FROM ABOUT 0.0001% TO ABOUT 0.0025%, BY WEIGHT, OF 2METHYL-3 PHYTYL, 1,4-NAPHTHOHYDROQUINONE. 